# The first of Fermat's last theorem

A simple question(s): When and by who was Fermat's famous conjecture (proved by Wiles et al.) called his "last theorem"? Was the original motivation the same as is given nowadays, that this would be the last-proved of his theorems?

It is interesting that so many accounts of its history were written which did not really mention the issue of its relatively mysterious naming.

My guess is that it was G. Lamé:

Memoire sur le dernier theoreme de Fermat C.R. Acad. Sci. Paris, 9, 1839, 45-46.

• That's a great guess. I'm going to look at that paper. It's great from Lamé to have named his paper with such humor, especially if he was the one coming up with the catchy name.
– plm
Jan 18, 2016 at 7:16
• I just read the whole paper! It's 1 page long. I am relatively confident this must have been the first publication using "dernier=last". The first sentence Lamé writes is: "De tous les théorèmes énoncés par Fermat un seul reste incomplètement démontré." (Of all the theorems stated by Fermat only one is still incompletely proved.) It's also a pretty awesome display of the difference of philosophy of mathematics between now and then. Mathematicians only "stated" theorem, now they only prove them. Thanks Franz, great tip.
– plm
Jan 18, 2016 at 7:33
• Incidently it also shows a slight difference of interpretation of "last theorem" with what we usually see nowadays. Lamé really did consider it a "theorem", so he did not have as much humor as we may believe, while modern writers called it "last theorem" ironically.
– plm
Jan 18, 2016 at 7:39

Fermat stated lots of conjectures, and announced to have proofs of many startling theorems without sharing said proofs in his correspondence. Famously, he scribbled on the margins of a copy of Diophantus "Arithmetic", scribblings which his son published after Fermat's death. Euler set to work on the missing proofs, and when he finished almost all his voluminous statements had been proven or disproven. One of the few that weren't resolved, and which caught the imagination, was the "last theorem" ("last" because it still had no proof, not because of any temporary order).

• This doesn't really seem to answer who and when was the first (time) that this theorem was called "Fermat's last theorem".
– Danu
Jan 17, 2016 at 21:12
• This does not answer my question at all, but thanks for commenting.
– plm
Jan 18, 2016 at 7:15